Stuart Lancaster reflected with pride on England's 2014 RBS 6 Nations, but identified the first quarter of the Championship opener in Paris as a source of regret.

The morning after Ireland sent Brian O'Driscoll into international retirement with a Six Nations title to cherish following a night of high drama at the Stade de France, Lancaster was left pondering the fine margins of success and failure.

A first Grand Slam since 2003 would have decorated his third Championship as head coach but for the individual brilliance of Gael Fickou, whose late try snatched a 26-24 victory for France six weeks ago.

Rather than the sublime footwork of Fickou, however, it was England conceding a first-quarter deficit of 16-3 that challenges the bright outlook Lancaster has adopted for an otherwise fine Six Nations.

When asked if he had any regrets, he responded: "Winning in France would have helped as a starting point.

"You can always look back in hindsight at moments in games and at decisions that you felt went against you, missed opportunities.

"I tend not to get drawn back to that extent. Instead I think about the development we've made as a group and all the positives of the performances.

"But there's no doubt about it, that first 20 minutes in France gave us a mountain to climb that ultimately cost us in the end.

"Overall you look back at the games and what we could have done differently, but overall the positives are there for everyone to see.

"We scored 14 tries over the tournament, seven against Italy, and I'm hugely proud of what we've achieved."

Ireland were crowned champions on points difference, despite England swamping Italy 52-11 in a seven-try rout at the Stadio Olimpico.

Only 11 points placed the Irish at the summit of the table and in private Lancaster must rue the failure to post bigger scores against Scotland in particular, but also against Wales and Italy.

Using points difference to settle the outcome contributed to a thrilling final day in a strong Six Nations, but can seem an arbitrary yardstick influenced by conditions and the erratic form of weaker teams. Lancaster, however, accepts the rule.

"It's worked pretty well - we all knew the score from the start," he said.

"We knew we were first up on the last day and we knew we'd enter the game with a six-day turnaround.

"Playing three away games makes it more challenging to try and win the Championship.

"We have three at home next year so it's a bit easier for us. The Championship works well and it was a pretty fitting climax."

England, who finished runners-up for a third successive year, emptied their bench at the Stadio Olimpico, inviting criticism from Sir Clive Woodward who claimed the changes disrupted the team's momentum.

"Whichever way you go you'll be criticised. You do what you believe is right for the team," Lancaster said.

"All the substitutions that came on against Italy made a hugely positive impact on the game and we're together as a group."

England's next assignment is their summer tour to New Zealand, on which Mike Brown will look to maintain the form that has made him arguably the best full-back in Europe.

Brown was named man of the match against Italy - remarkably the third time he has taken the award in four games - and is the overwhelming favourite to be crowned player of the Championship.

"New Zealand are the number one team in the world and we're going to their back yard. It's a great challenge for us," Brown said.

"Now that this Six Nations is done and dusted, we're excited about New Zealand. It will be great. We aspire to achieve what they've achieved and to be like them.

"There's a lot of confidence in the squad that we can push New Zealand.

"We're making strides with our attacking game and can make teams uncomfortable in defence and attack."